Security: Understanding DNS Attacks

Understanding the mechanics behind DNS is important when securing your DNS server. DNS is robust and full featured; understanding what resources each DNS action requires will allow administrators to disable unnecessary features, therefore achieving a minimalist and secure DNS server. This section reviews the basics of DNS mechanics. Domain name information is stored in flat text files called zone files. User requests and server replies are simple text-file searches and take very few system resources. Some newer DNS technologies allow for write access to update record data and other configurations remotely. However, unless write access is explicitly enabled, from an end user perspective DNS should be referred to as a read-only service. DNS is mechanically broken up into records, servers, and their respective chains of authority from the root servers...